Occasionally, military rocket-driven projectiles may be exposed to the heat of a fire which may become sufficiently intense to ignite the propulsion charge in the military propulsion rocket motor, whereby the warhead of the military projectile is propelled in an uncontrolled manner, with potentially disastrous results. To prevent any such disastrous results, a need exists to provide a releasable joint construction for use between a military rocket motor and its warhead whereby the heat of a fire causes disconnection of the joint between the military rocket motor and its warhead at a relatively low temperature, before the rocket motor is heated to a sufficiently high temperature to ignite the propellant charge therein. In many cases, the action of gravity will cause separation of the warhead from the rocket motor. In any event, the rocket motor should be constructed and arranged to cause immediate separation of the warhead from the rocket motor if the propellant charge is ignited by the heat of a fire or the like.